Near-infrared study of CIZA J1324.7-5736, the second richest cluster of galaxies in the Great Attractor

We present the result of a deep near-infrared survey of the newly identified X-ray luminous cluster of galaxies CIZA J1324.7-5736 in the Great Attractor (GA) region. In a 35 × 35 arcmin² region, 111 galaxy candidates with   r _{Ks 20} > arcsec  are identified. Comparison of the extinction-corrected   K _s   -band luminosity function of CIZA J1324.7-5736 with those of nearby clusters indicates that the richness class of CIZA J1324.7-5736 is almost the same as, or richer than, the Pavo, Centaurus and Hydra clusters but poorer than the Coma, Perseus and Norma clusters. CIZA J1324.7-5736 is possibly the second richest cluster in the GA region following the Norma cluster. The position of CIZA J1324.7-5736 [in the ( l , b , v ) space] is close to the Centaurus–Crux cluster and the agglomeration of galaxies detected by the Parkes H  i survey. CIZA J1324.7-5736, together with the Centaurus–Crux cluster and the H  i galaxy agglomeration, is most likely to be one of the richest local concentrations in the GA overdensity of galaxies.     

用X射线分析显微镜对海藻元素的研究Ⅲ. X射线分析显微镜引导下羊栖菜中含溴化合物的分离

本研究采用了一种新的元素检测方法,即用X射线分析显微镜来引导分离羊栖菜(Sargassum fusiformis)中有机溴化合物。新鲜羊栖菜经提取、浓缩、洗脱等处理,所得洗脱液经冷冻干燥后,用X射线分析显微镜分析其元素组成。X射线荧光光谱得到的结果表明,这种检测方法十分有效,能够证实有机溴化合物在PVPP柱色谱中得到了有效的浓缩与分离。MALDI-TOFMS质谱显示存在两个有机溴化合物,分子量分别为330和554,质谱的同位素特征表明,每个有机溴化合物分子中分别含有一个溴原子。该有机溴化物具有以下的化学特征:水溶性较强,能够被PVPP柱吸附,而在弱碱条件下溶出;在水溶液中不太稳定,容易形成沉淀。该有机溴化物的紫外可见光谱特征具有多酚化合物的特点,并与海藻中的砷化物具有某种程度的相互作用。     

用X射线分析显微镜对海藻元素的研究Ⅱ.裙带菜孢子叶的元素定位

X射线分析显微镜是一种快速的非破坏分析方法,可以用来对海藻中特定的元素在组织水平进行定位。本实验采用X射线分析显微镜对1997年2月在日本佐贺县唐津市海岸采集的养殖裙带菜(Undaria pinnatifida Suringar)的孢子叶进行了硫、钾、钙、碘的组织定位研究,对孢子叶的整体进行X射线扫描及特征元素次级荧光的图像分析,并选取孢子叶的边缘部、中部及中心各一点进行定点的X射线荧光光谱测定。Ⅹ射线荧光光谱的结果表明,钾是裙带菜孢子叶的最显著元素,具有最大的X射线荧光强度。定位分析表明,钾在孢子叶的中心部位分布较高,钙与碘则在边缘部分布较高,硫多位于孢子叶的中间部分,在中心部位及边缘部的分布均较低。除了钾、钙、硫以外,其他元素如铁、溴、锌也能够在X射线荧光光谱中给出谱峰。作者得到的X射线特征元素荧光图像首次报道了裙带菜孢子叶中钾、钙、硫等元素在组织水平的定位。应用RGB图像彩色合成技术获得的硫、钙、钾三元素的彩色合成图像也与定点分析结果相一致。     

Effects of a uniaxial compression on remanent magnetizations of igneous rocks

Summary Characteristics of remanent magnetization of an igneous rock under a uniaxial compression are divided into those of the soft component and those of the hard component. The soft component of remanent magnetization irreversibly decreases with an increase of compression () regardless whether the axis of is parallel or parpendicular to the direction of magnetization. The hard component changes reversibly with : the magnetic intensity of hard component increases with when the axis of is perpendicular to the magnetization, whereas it decreases with when the axis of is parallel to the magnetization.Theoretically, the irreversible change of the soft component is attributable to the irreversible movement of 90° domain walls which results in the pressure demagnetization effect, while the reversible change of the hard component is due to the reversible rotation of spontaneous magnetization within those domains which are so tightly fixed by large effective anisotropy energy that the induced magnetoelastic energy cannot drive their 90° walls.In natural remanent magnetization of igneous rocks, the soft component corresponds to either one or all of isothermal remanent magnetization, viscous remanent magnetization and piezo-remanent magnetization, whereas the hard component is mostly due to thermo-remanent magnetization.     

Introductory notes on shock remanent magnetization and shock demagnetization of igneous rocks

Summary Effects of mechanical shocks of about 0.5 msec in duration on the remanent magnetization of igneous rocks are experimentally studied. The remanent magnetization acquired by applying a shock (S) in the presence of a magnetic field (H), which is symbolically expressed asJ _R (H₊S H_o), is very large compared with the ordinary isothermal remanent magnetization (IRM) acquired in the same magnetic field.J _R (H₊S H_o) is proportional to the piezo-remanent magnetization,J _R (H₊P₊P_o H_o).The effect of applyingS in advance of an acquisition of IRM is represented symbolically byJ _R (S H₊ H_o).J _R (S H₊ H_o) can become much larger than the ordinary IRM, and is proportional to the advance effect of pressure on IRM,J _R(P₊ P₀ H₊ H₀).The effect of shockS applied on IRM in non-magnetic space is represented by the shock-demagnetization effect,J _R(H₊ H₀ S), which also is proportional toJ _R(H₊ H₀ P₊ P₀).Because, the duration of a shock is very short, a single shock effect cannot achieve the final steady state. The effect ofn-time repeated shocks, is represented byJ ₀+J ^*(n), whereJ ₀ means the immediate effect and J ^*(n) represent the resultant effect of repeating, which is of mathematical expression proportional to [1–exp {–(n–1)}].

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Zusammenfassung Die Effekte des mechanischen Stosses mit der Dauer von etwa 0.5 ms auf der remanenten Magnetisierung wurden experimentell nachgesucht. Das erworbene Remanenz der Magnetisierung nach dem Stoss (S) unter dem magnetischen Feld (H), das hier symbolisch alsJ _R(H₊ SH₀) bezechnet wird, ist sehr stark im Vergleich mit der normalen isothermischen remanenten Magnetisierung (IRM) unter demselben magnetischen Feld.J _R(H₊ S H₀) ist im Verhältnis zur piezoremanenten Magnetisierung,J _R(H₊ P₊ P₀ H₀).Der Effekt vom Stoss vor der Erwerbung von IRM wird symbolisch alsJ _R(S H₊ H₀) bezeichnet.J _R(S H₊ H₀) kann viel stärker als die normale IRM werden, im verhältnis zum Effekt des vorausgegebenen Drucks auf IRMJ _R(P₊ P₀ H₊ H₀).Der Effekt des Stosses auf IRM im Raum ohne magnetisches Feld wird mit dem Stossentmagnetisierungseffekt dargestellt,J _R(H₊ H₀ S), der auch proportional zuJ _R(H₊ H₀ P₊ P₀) ist.Da die Dauer einzelnen Stosses sehr kurz ist, kann der Effekt des einmaligen Stosses den endgültigen stabilen Zustand nicht erreichen. Der Effekt nachn-maligen wiederholten Stossen wird alsJ ₀+J ^*(n) bezeichnet, wobeiJ ₀ den unverzüglichen Effekt bedeutet, und J ^*(n) beschreibt den resultanten Effekt der Stosswiederholung, dessen mathematische Darstellung proporational zu [1–exp {–(n–1)}] ist.

     

Bispectra of spike-array type time series and their application to the analysis of oceanic microstructures

Bispectral analysis is applied to records of the vertical profile of the vertical temperature gradient in the oceanic thermocline in the San Diego Trough. The bispectra exhibit three notable features; (1) bispectral peaks at the points (0.2 m^–1, 0.2 m^–1) and (0.2 m^–1, 0.1 m^–1), (2) bispectral ridges along the lines ( ₁= ₀, ₂= ₀ and ₁+ ₂= ₀ corresponding to peak wavenumbers ₀ in power spectra, and (3) array of bispectral peaks of interval of 0.2 m^–1 The results are compared with the bispectra of several modeled time series of spike-array type. The periodicity of 5 m found in the records seems to have two meanings: spacing of predominant spikes and wavelength of predominant sinusoidal wave. If this indicates the existence of internal waves having a vertical wavelength the same as the scale of homogeneous layers, it would suggest the possible importance of internal waves in the formation and maintenance mechanisms of oceanic microstructure.     

Basin-Scale Geographic Patterns of Bacterioplankton Biomass and Production in the Subarctic Pacific, July–September 1997

Bacterial biomass and production rate were measured in the surface (0–100 m) and mesopelagic layers (100–1,000 m) in the subarctic Pacific and the Bering Sea between July–September, 1997. Depth profiles were determined at stations occupied in oceanic domains including the subarctic gyres (western, Bering Sea, and Gulf of Alaska) and a boundary region south of the gyres. In the surface layer (0–100 m), both bacterial biomass and production were generally high in the western and Bering Sea gyres, with the tendency of decrease toward east. This geographic pattern was consistent with the dominant regime of phytoplankton biomass at the time of our survey. A significant portion of variation in bacterial production was explained by the concentration of chlorophyll a (r ² = 0.340, n = 60, P < 0.001) and, to the greater extent, by the concentration of semilabile total organic carbon (SL-TOC = TOC at a given depth—TOC at 1,000 m, r ² = 0.488, n = 59, P < 0.0001). Temperature significantly improved the regression model: temperature and chlorophyll jointly explained 60% of variation in bacterial production. These results support the hypothesis that bacteiral growth is largely regulated by the combination of temperature and the supply of dissolved organic carbon in subarctic surface waters. In the mesopelagic layer (100–1,000 m), the geographic pattern of bacterial production was strikingly different from the surface phytoplankton distribution: the production was high in the boundary region where the phytoplankton biomass was lowest. Bacterial growth appeared to be largely controlled by the supply of organic carbon, as indicated by the strong dependency of bacterial production on SL-TOC (r ² = 0.753, n = 75, P < 0.0001). The spatial uncoupling between surface phytoplankton and mesopelagic bacterial production suggests that the supply rate of labile dissolved organic carbon in the mesopelagic zone does not simply reflect the magnitude of the particulate organic carbon flux in the subarctic Pacific.     

Numerical study of the behavior of heated water discharged into the ocean

Matsuno and Nagata (1987) showed numerically that the spreading characteristics of the discharged heated water from power plants of existing scale is significantly influenced by the earth's rotation effect. Although the effect of the enhancement of the Coriolis parameter on the spreading characteristics of the formed warm water mass was discussed in order to demonstrate the rotation effect, other parameters such as the density difference between the discharged heated water and ambient water and the vertical eddy viscosity and diffusivity were fixed. In this paper, the dependence of the spreading characteristics on these parameters is examined. Then, it is shown that the overall shape of the formed warm water mass and density and velocity structure strongly depend on these parameters. Also, it is indicated that the behavior of the warm water mass under the rotation effects is too complicated to be described with a few parameters. For example, the internal radius of deformation seems to be one of the determinative parameters, and the increase of the density difference between discharged water and ambient water has a similar effect on the shape of the formed warm water mass as a decrease of the Coriolis parameter. However, a change of the two values has different effects on the detailed density structure and current structure of the warm water mass. The Prandtl number seems to determine some aspects of the veloczty field such as velocity magnitude and width of the southward flowing current zone. However, other features such as the thickness of the warm water mass are not determined by the Prandtl number.